Field of the Invention
The present invention relates to an ink jet recording method and an ink jet recording device.
Description of the Related Art
Recently, there are more and more opportunities for using an ink jet recording device in the field of commercial printing or office printing. In the field of commercial printing or office printing, it is required to have a pigment ink for having excellent optical density of an image to be obtained. In general, the optical density of an image to be obtained can be enhanced by increasing the aggregation property of a pigment. In order to enhance the optical density of an image to be obtained, various kinds of ink have been investigated. A pigment ink containing self-dispersion pigment, urethane resin, and polyethylene glycol has been suggested (see, Japanese Patent Application Laid-Open Nos. 2013-253237 and 2013-253238). A pigment ink containing self-dispersion pigment, water soluble resin, surface active agent, and penetration solvent has been also suggested (see, Japanese Patent Application Laid-Open No. 2015-117332).
However, when the aggregation property of a pigment is enhanced, the pigment can easily aggregate also at ejection opening of a recording head, and thus it is difficult to obtain the sticking recovery property of ink. Since the optical density of an image and the sticking recovery property of ink are in trade-off relationship, it is difficult to have both the optical density of an image and the sticking recovery property of ink at high level.
To increase the recording speed, the inventors of the present invention applied the ink described in Japanese Patent Application Laid-Open Nos. 2013-253237, 2013-253238, and 2015-117332 to so-called one pass recording, and carried out the investigation. In the case of applying the one pass recording, an effort should be made for increasing the optical density of an image that is higher than before. However, it was found that, even when an image is recorded by using the ink described in Japanese Patent Application Laid-Open Nos. 2013-253237 and 2013-253238, which has been designed so as to have the optical density, the optical density is not obtained at the level that is required in recent days. Meanwhile, when an image is recorded by using the ink described in Japanese Patent Application Laid-Open No. 2015-117332, a certain amount of the optical density is obtained but it is still at an insufficient level, and thus it was found that there is still room for improvement. It was also found that, when the ink described in Japanese Patent Application Laid-Open No. 2015-117332 is left to stand for a long period of time while it is mounted in an ink jet recording device, the sticking recovery property of ink also becomes insufficient in conjunction with moisture evaporation of ink near ejection opening of a recording head.